How To Cool Down A Furnace

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1 Plant engineering and waste heat systems for the iron and steel industry

2 2 3 Profitable and environmentally friendly Waste heat systems for the iron and steel industry At home in the world Oschatz best technology backed by experience Oschatz is a plant constructor operating worldwide. With more than 160 years of experience behind it, the company now has about 1,200 employees and has subsidiaries, representative offices and branches around the globe. Our plants for cooling waste gases and converting recovered heat into industrially utilisable steam are used throughout the world in the fields of iron and steel metallurgy, non-ferrous metallurgy and chemical as well as power plant industry. Iron and steel metallurgy has had a high priority to Oschatz for many years. In order to relieve the environment and to recover the heat energy in waste gases, Oschatz develops problem solutions for cooling the hot, highly dust-loaded and carbon monoxide containing waste gases from production plants. Each plant concept is based on customer and process-specific requirements, to ensure the highest degree of availability, operational safety and profitability for the customers. Depending on their destination, the plants and components are fabricated in the two extremely modern production facilities in Kocaeli, Turkey, The deflection bend of a converter (BOF) cooling stack is installed at the Tata Steel IJmuiden steel works. and Nanjing, China. Naturally, we comply with all quality standards, such as ISO 9001, ASME standard, Pressure Equipment Directive, EU standards etc. All Oschatz products are highly profitable, easy to maintain and offer easy accessibility to the individual components. To ease the burden on the environment and make use of the thermal energy in waste gases, Oschatz has developed systems for cooling the hot, heavily dust-laden, carbon-containing waste gases from iron and steel production plants. Oschatz designs, produces and installs complete converter waste gas cooling systems for oxygen steel works for international steel producers. These systems, also called cooling stacks, convert the generated process heat into steam that can be used for industrial purposes. Oschatz also manufactures waste heat boilers for installation downstream of both sinter belts and sinter coolers and for use in coking plants and coke dry quenching plants. As usual with plants from Oschatz, each concept is based on the customer s individual wishes and requirements. This is the only way that these systems achieve the ultimate degree of operational reliability and economic efficiency that is expected of plants Made by Oschatz throughout the world. Oxygen steel plants Converter waste gas cooling plants (cooling stacks) for waste gas from top and bottom blowing converters for full combustion and suppressed combustion with gas recovery. Waste heat boiler downstream of sinter cooler at the Tata steelworks in IJmuiden, Netherlands Sinter plants Waste heat boilers downstream of sinter belts and sinter coolers with and without auxiliary firing and incorporating hot air recirculation from sinter coolers as combustion air for auxiliary burners Coking plants Waste heat boilers in coking plants Modernising plants Over the last few years, Oschatz has specialised in modernising existing steel works plants by renewing the lower hood parts with optimal gas collection in order to meet the new environmental protection requirements. Additional energy extraction is achieved, because the cleaned carbon monoxide containing gas is not flared up as with previous systems, but can be discharged continuously via a downstream accumulator.

3 4 5 3D illustration of a converter cooling plant with piping Pioneering Technologies Partner for innovation Utilize heat Obsolete methods and intensified competition on the international stage are increasingly forcing steel producers to introduce new, more profitable production techniques. Plant components that work flawlessly and reliably, and are specifically designed to operate cost-effectively, form the basis that paves the way for these trend-setting processes. Oschatz has the requisite knowhow and can offer the technological solutions to master the wide-ranging problems in the field of waste heat recovery, which is becoming ever more important. Cooling plants for converter waste gases Oschatz designs and fabricates tailor-made waste gas cooling plants worldwide. Customers can select one out of the following two cooling processes: Evaporation cooling Pressurized water cooling using nitrogen pressure for high and low pressure in the closed circuit Pressurized water plants are operated within a pressure range of 10 to 32 bar and at temperatures between approx. 50 and 220 C in forced circulation. The plants with evaporation cooling, operate in natural or forced circulation or in combined operation. Oschatz converter waste gas cooling plant with a liftable and lowerable skirt down-stream of a basic oxygen furnace (BOF) The steam produced during the process is stored for energy recovery in accumulators assuring a continous steam flow to the works steam network. It can also be condensed or blown off unutilized. The operating pressure for evaporation cooling plants can be between 0.5 and 64 bar. The amount of saturated steam being produced can be superheated externally if needed. Comply with environmental requirements As authorities all over the world have issued more strict environmental requirements over the last few years, Oschatz has been revamping older steelworks more and more frequently. To this effect, particular emphasis is being placed on achieving optimal gas collection by renewing the lower hood parts. Experience as the basis for new developments When it comes to designing the waste gas cooling systems to be built to meet its customers individual requirements, Oschatz is able to draw upon many years of comprehensive experience relating to the planning and production of converter cooling stacks. Maximum efficiency in optimisation of the steel production process is obtained in particular from the round design conceived by Oschatz, the advantages of which include high levels of operational reliability and the long service life of the components. Waste gas cooling sections designed according to this principle have already been used in 2005 in connection with the HIsmelt process, and are currently used in the HIsarna process. Shaping the future The HIsarna process was developed as part of the ULCOS (Ultra-Low Carbon Dioxide (CO 2) Steelmaking) project, the aim of which is to halve the emissions of carbon dioxide arising during steel production. In the HIsarna process the preheating and partial pyrolysis of the coal in the reactor, the melting cyclone for melting iron ore and the melting crucible for subsequent reduction of the iron ore and iron extraction are all combined. This process greatly reduces the consumption of coal, and consequently results in a significant cut in carbon dioxide emissions. The waste gases containing carbon monoxide that are produced in the course of the HIsarna process are combusted in the waste gas cooling section specially developed by Oschatz for this method, installed above the smelting reactor, and are cooled with the aid of water. The water is then cooled via a secondary circuit before being fed back to the waste heat system. While the test plant is already delivering very good operational results and is meeting the strict customer requirements perfectly, for commercial implementation of the HIsarna process it is envisaged that the waste heat will be utilised in the form of economically and ecologically sustainable evaporative cooling. The advantages of the Oschatz-specific construction are: Greater resistance to high gas-side overpressure Reduced tendency towards accretions More uniform heat transfer More favourable flow conditions Waste gas cooling plant for the HIsarna process in IJmuiden, Netherlands

4 6 7 Oschatz Services & Solutions k.s. Installation of a skirt with double mechanical sealing Innovative and reliable Developed with the customers: Oschatz skirts Designing the lowest cooling hood component to match the converter dimensions is crucial for optimal collection of the primary gases coming from the converter. This applies in particular to y air factors of 0.05 to 0.1. Oschatz has developed and designed the necessary skirts in tube design in cooperation with well-known steelworks and gas cleaning companies. Thus, since 1969, Oschatz has already been supplying skirts in tube design with water seal to Thyssen AG in Duisburg, Somisa, Argentina and Inland Steel, USA. In 1973, skirts in tube design with external ring, i.e. with a labyrinth seal, were installed for the first time at SSAB-Lulea, Sweden. Oschatz has developed a skirt for particularly tight spaces around the hood, for which neither a water seal nor an external ring can be used, using nitrogen or steam as a sealing agent. These skirts were installed at SSAB-Lulea, Sweden in 1982 in the context of plant reconstruction for waste gas recovery with gas accumulation. An Oschatz solution, which has since proven itself in numerous plants. The further development of this skirt was incorporated at ThyssenKrupp Steel AG in Duisburg in 2000 and is used without a sealing agent. Sealing of the space between the skirt and the hood is effected using a double mechanical seal. This consists of copper sheets, which are screwed to a flange on the top of the skirt. Meanwhile, Oschatz has applied for a patent for the design of this skirt. Even the best product can go wrong some time; parts may need to be repaired or replaced. In such instances, our customers can rely on the expert service provided by Oschatz. Our subsidiary Oschatz Services and Solutions k.s. pulls out all the stops to keep downtimes at your plant to an absolute minimum. The speedy availability of spare parts, which can be installed on site by our specialists if required, helps us ensure that your plant can resume production as quickly as possible. The components are built or repaired in the OSS manufacturing facility in Zlíchov Praha. Total floor space: 850 m2 (7879 ft 2). Expert support around the clock Throughout the world, expert Oschatz employees are the key to obtaining the best-quality products. What our service provides: The quickest possible plant availability in the event of breakdown or repair Highly qualified repair personnel with plant-specific know-how 24/7 emergency service Consulting services from our team: Optimisation of operating costs Improved technical and personnel planning of resources and costs Planning of environmental protection measures Conversion of furnaces Performance-enhancing adjustment of steam parameters Our service team is ready to help you around the clock. The OSS manufacturing facility in Zlíchov Praha ensures the speedy availability of spare parts.

5 Oschatz GmbH Westendhof Essen Germany Phone Fax Production plant in Nanjing, China Manufacturing plant in Kocaeli, Turkey Oschatz has been producing boilers and waste heat systems at its plant in Turkey for customers all around the world since In 2010, in an initial expansion phase, a new plant was built in the free trade zone in the Kocaeli region, roughly 120 km south-east of Istanbul. As of 2011, plants and components are being manufactured in accordance with ASME standards, the Pressure Equipment Directive, TRD/AD standards and ISO 9001 in four new, modern workshops with a total production area of 10,000 m 2 (108,000 ft 2 ) on the 60,000 m 2 (646,000 ft 2 ) site. The superlative location, directly on the Sea of Marmara, provides ideal logistic conditions. The production site in Turkey offers capacity for around 450 employees. Photo: Thomas Bittera To be able to supply the markets in Asia, Australia and Oceania faster and more cost-effectively, Oschatz has built a second production plant in Nanjing, China. Production at the plant began in October A second expansion phase at this plant was completed only three years later in the summer of In seven bays with a total floor space of 15,000 m 2 (161,000 ft 2 ), located on a 50,000 m 2 (538,000 ft 2 ) site with good connections to the port of Changjiang, Oschatz now manufactures waste heat boilers and cooling stacks in accordance with the Chinese GB, ASME, TRD/AD and ISO 9001 standards. About 600 employees work here under European management, in sales, engineering/ design, in production, finance and procurement.